Irradiation-curable silicone compositions, photo-active platinum (IV) compounds, and method

Abstract

Cyclopentadienylplatinum (IV) compounds having a trisubstituted-silyl aliphatic group attached to platinum by carbon-platinum linkages have been found to be photo-active and effective as hydrosilylation catalysts in irradiation-curable silicone mixtures.

What is claimed is: 
     
       1. A photo-active cyclopentadienylplatinum (IV) compound having a trisubstituted-silyl aliphatic group attached to platinum by a carbon-platinum bond. 
     
     
       2. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 1, where the cyclopentadienyl is substituted with at least one aromatic organic radical. 
     
     
       3. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 1, where the cyclopentadienyl is substituted with at least one aliphatic organic radical. 
     
     
       4. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 1, where the cyclopentadienyl is substituted with a mixture of at least one aromatic organic radical and at least one aliphatic organic radical. 
     
     
       5. Photo-active cyclopentadienylplatinum (IV) compounds having the formula,   [(R.sup.1).sub.a (R.sup.2).sub.b Cp]Pt(R.sup.3 R.sup.4)Q     where R 1  is a C 6-20  aromatic radical, R 2 , R 3 , and R 4  are each independently a C 1-22  aliphatic organic radical, Cp is a cyclopentadienyl radical, Q is a silicon-containing organic sensitizing group, "a" and "b" are whole numbers independently equal to 0 to 5 inclusive, and the sum of "a+b" is equal to 0 to 5 inclusive.   
     
     
       6. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 5, where Q is --R 5  Si(R 6 ) 3 , R 6  is a C 1-12  organic radical, and R 5  is a C 1-4  alkylene or alkylidene radical. 
     
     
       7. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 5, where R 1  is phenanthryl. 
     
     
       8. A photo-active cyclopentadienylplatinum (IV) compound in accordance with claim 5, where R 1  is naphthyl. 
     
     
       9. The compound (cyclopentadienyl)dimethyltrimethylsilylmethyl platinum. 
     
     
       10. The compound [1-methyl-3-(2'-naphthyl)cyclopentadienyl]dimethyltrimethylsilylmethyl platinum. 
     
     
       11. The compound [1-methyl-3-(9'-phenanthryl)cyclopentadienyl]dimethyltrimethylsilylmethyl platinum. 
     
     
       12. A method for making platinum (IV) compounds of the formula,   [(R.sup.1).sub.a (R.sup.2).sub.b Cp]Pt(R.sup.3 R.sup.4)Q     where R 1  is a C 6-20  aromatic radical, R 2 , R 3 , and R 4  are each independently a C 1-22  aliphatic organic radical, Cp is a cyclopentadienyl radical, Q is a silicon-containing organic sensitizing group, "a" and "b" are whole numbers independently equal to 0 to 5 inclusive, and the sum of "a+b" is equal to 0 to 5 inclusive, comprising, effecting reaction between a cyclopentadienide compound of the formula     (R.sup.1).sub.a (R.sup.2).sub.b CpM,     and a platinum (IV) compound of the formula,     XPt(R.sup.3 R.sup.4)Q,     where M is a metallic anion, and X is an anionic leaving group.   
     
     
       13. A method in accordance with claim 12, where X is halogen. 
     
     
       14. A method in accordance with claim 12, where R 1  is phenanthryl. 
     
     
       15. A method in accordance with claim 12, where R 1  is naphthyl. 
     
     
       16. A method in accordance with claim 12, where Q is --R 5  Si(R 6 ) 3 , R 6  is a C 1-12  organic radical, and R 5  is a C 1-4  alkylene or alkylidene radical. 
     
     
       17. A platinum (IV) compound having the formula,   XPt(R.sup.3 R.sup.4)Q,     where Q is a silicon-containing group having the formula,     --R.sup.5 Si(R.sup.6).sub.3,     X is an anionic leaving group, R 3  and R 4  are each independently a C 1-22  aliphatic organic radical, R 6  is a C 1-12  organic radical, and R 5  is a C 1-4  alkylene or alkylidene radical.   
     
     
       18. A platinum(IV) compound in accordance with claim 17, where X is a halogen radical. 
     
     
       19. The compound IPt(CH 3 ) 2  CH 2  Si(CH 3 ) 3 . 
     
     
       20. A method for making a platinum (IV) compound having the formula,   XPt(R.sup.3 R.sup.4)Q,     comprising the steps of,   (a) effecting a reaction between (i) a platinum (II) compound, ZPt(R 3 )X, and (ii) a silicon-containing aliphatic sensitizing group, MQ, to form a platinum (II) compound having the formula,   ZPt(R.sup.3)Q, and       (b) effecting the displacement of Z by effecting reaction between the platinum (II) compound of (a) and a haloaliphatic compound XR 4 , where Z is a C 7-10  cyclodienyl group, Q is --R 5  Si(R 6 ) 3 , M is a metallic anion, X is an anionic leaving group, R 3  and R 4  are each independently a C 1-22  aliphatic organic radical, R 6  is a C 1-12  organic radical, and R 5  is a C 1-4  alkylene or alkylidene radical.   
     
     
       21. A method for making a platinum (IV) compound in accordance with claim 20, where X is a halogen. 
     
     
       22. A method for making a platinum (IV) compound in accordance with claim 20, where Z is a 1,4-cyclooctadienyl group. 
     
     
       23. A method for making a platinum (IV) compound having the formula,   IPt(CH.sub.3).sub.2 CH.sub.2 Si(CH.sub.3).sub.3,     comprising the steps of   (c) effecting reaction between a platinum (II) compound, C 8  H 12  Pt(CH 3 )Cl, and a silicon-containing aliphatic sensitizing group LiCH 2  Si(CH 3 ) 3 , to form a platinum (II) compound having the formula,   C.sub.8 H.sub.12 Pt(CH.sub.3)CH.sub.2 Si(CH.sub.3).sub.3,     and     (d) effecting reaction between the platinum (II) compound of (c) and methyl iodide.   
     
     
       24. An irradiation-curable silicone composition comprising, (a) a polydiorganosiloxane having at least two alkenyl radicals attached to silicon by carbon-silicon bonds, where the alkenyl radicals can be in the terminal position, or in the polymer backbone, or a combination thereof,   (b) a silicon hydride cross-linker, and,   (c) an effective amount of a photo-active cyclopentadienylplatinum (IV) compound having a trisubstituted-silyl aliphatic group attached to platinum by carbon-platinum bonds which is sufficient to effect the cure of the irradiation-curable silicone composition.   
     
     
       25. An irradiation-curable silicone composition comprising, (d) a polydiorganosiloxane having at least two alkenyl radicals attached to silicon by carbon-silicon bonds, where the alkenyl radicals can be in the terminal position, or in the polymer backbone, or a combination thereof,   (e) a silicon hydride cross-linker, and,   (f) an effective amount of a photo-active platinum (IV) compound having the formula,   [(R.sup.1).sub.a (R.sup.2).sub.b Cp]Pt(R.sup.3 R.sup.4)Q,     which is sufficient to effect the cure of the irradiation-curable silicone composition, where R 1  is a C 6-20  aromatic radical, R 2 , R 3 , and R 4  are each independently a C 1-22  aliphatic organic radical, Cp is a cyclopentadienyl radical, Q is a silicon-containing organic sensitizing group, "a" and "b" are whole numbers independently equal to 0 to 5 inclusive, and the sum of "a+b" is equal to 0 to 5 inclusive.     
     
     
       26. An irradiation-curable silicone composition consisting essentially of, (g) a polydiorganosiloxane having at least two alkenyl radicals attached to silicon by carbon-silicon bonds, where the alkenyl radicals can be in the terminal position, or in the polymer backbone, or a combination thereof,   (h) a silicon hydride cross-linker, and,   (i) a photo-active platinum (IV) compound selected from the group consisting of (cyclopentadienyl)dimethyltrimethylsilylmethylplatinum, [1-methyl-3-(2'-naphthyl)cyclopentadienyl]dimethyltrimethylsilylmethylplatinum, and [1-methyl-3-(9'-phenanthryl)-cyclopentadienyl]dimethyltrimethylsilylmethylplatinum,   in an effective amount which is sufficient to effect the cure of the Irradiation-curable silicone composition.   
     
     
       27. A method of coating a substrate with a cured tack-free silicone film, which comprises, (1) applying onto the surface of the substrate to a thickness of about 0.5 to about 5 mil, an irradiation-curable silicone composition comprising, (a) a polydiorganosiloxane having at least two alkenyl radicals attached to silicon by carbon-silicon bonds, where the alkenyl radicals can be in the terminal position, or in the polymer backbone, or a combination thereof,   (b) a silicon hydride cross-linker, and,   (c) an amount of a photo-active cyclopentadienylplatinum (IV) compound having a trisubstituted-silyl aliphatic group attached to platinum by carbon-platinum bonds which is sufficient to effect the cure of the irradiation-curable silicone composition, and     (2) irradiating the surface of the applied irradiation-curable silicone composition with light in the range of 240-400 nm.   
     
     
       28. A method according to claim 27 wherein, the photo-active cyclopentadienylplatinum (IV) compound has the formula   [(R.sup.1).sub.a (R.sup.2).sub.b Cp]Pt(R.sup.3 R.sup.4)Q,     where R 1  is a C 6-20  aromatic organic radical, R 2 , R 3 , and R 4  are each independently a C 1-22  aliphatic organic radical, Cp is a cyclopentadienyl radical, Q is a silicon-containing organic sensitizing group of the formula --R 5  Si(R 6 ) 3 , R 6  is a C 1-12  organic radical, and R 5  is a C 1-4  alkylene or alkylidene radical, "a" and "b" are whole numbers independently equal to 0 to 5 inclusive, and the sum of "a+b" is equal to 0 to 5 inclusive.   
     
     
       29. A method according to claim 27, where the photo-active cyclopentadienylplatinum (IV) compound is [1-methyl-3-(9'-phenanthryl)cyclopentadienyl]trimethyl platinum. 
     
     
       30. A method according to claim 27, where the substrate is cellulose-based. 
     
     
       31. A substrate coated with an irradiation-curable silicone composition comprising, a platinum (IV) compound having the formula,   [(R.sup.1).sub.a (R.sup.2).sub.b Cp]Pt(R.sup.3 R.sup.4)Q,     and any reaction products thereof, where R 1  is a C 7-20  aromatic organic radical, R 2 , R 3 , and R 4  are each independently a C 1-22  aliphatic organic radical, Cp is a cyclopentadienyl radical, "a" and "b" are whole numbers independently equal to 0 to 5 inclusive, and the sum of "a+b" is equal to 0 to 5 inclusive.   
     
     
       32. A substrate according to claim 31, in which the silicone coating composition has been irradiation-cured. 
     
     
       33. A substrate according to claim 31, which is cellulose-based. 
     
     
       34. A substrate according to claim 33, in which the silicone coating composition has been irradiation-cured.